National signing day and the deadline for underclassmen to enter the NFL draft are behind us. So it's a good time to revise the way-too-early preseason Top 25 for the 2008 college football season. Ohio State, Tennessee and USC moved up. Florida, West Virginia and Michigan moved down. In fact, the Wolverines fell out of the Top 25 after quarterback Ryan Mallett transferred to Arkansas and top QB recruit Terrelle Pryor delayed announcing his college choice.

Quarterback Matthew Stafford and tailback Knowshon Moreno have Georgia poised to contend for a national championship. But there will be plenty of hurdles. With the annual neutral-site contest against Florida (in Jacksonville) and road games at Arizona State, LSU and Auburn, the Bulldogs will play one of the country's toughest schedules. If they can navigate their way through it with two or fewer losses, the Bulldogs have a chance to play in the BCS title game.

The Sooners lost three very good juniors -- receiver Malcolm Kelly, linebacker Curtis Lofton and cornerback Reggie Smith -- to the NFL draft. But with tailback DeMarco Murray and QB Sam Bradford coming back, the Sooners' offense could be explosive. The Big 12 schedule is favorable: Oklahoma doesn't play Missouri and gets Kansas and Texas Tech at home.

The Buckeyes fared much better than expected in personnel losses, with only junior defensive end Vernon Gholston declaring for the NFL draft. All-America linebacker James Laurinaitis returns to lead what should be a very stingy defense, and tailback Beanie Wells will be a Heisman Trophy candidate. Ohio State is good enough to go through the Big Ten schedule unbeaten, but a Sept. 13 road trip to USC might decide its BCS title hopes.

The Trojans will have to rebuild their offense with quarterback John David Booty and tight end Fred Davis leaving. The defense also takes several hits, with end Lawrence Jackson, tackle Sedrick Ellis and linebacker Keith Rivers also leaving. But if USC can avoid the injuries that hampered it in 2007 -- and if Mark Sanchez or Arkansas transfer Mitch Mustain plays well at quarterback -- the Trojans again will be a national championship contender.

With quarterback Chase Daniel returning for his senior season and 10 starters coming back on defense, the Tigers should be good enough to challenge Oklahoma and Texas for the Big 12 championship. The schedule sets up nicely, as Missouri doesn't play Oklahoma, Texas A&M or Texas Tech in the regular season.

Losing tailback Jamaal Charles to the NFL draft might be a tremendous blow on offense, but coach Mack Brown went a long way toward rebuilding his defense by hiring Auburn coordinator Will Muschamp. Quarterback Colt McCoy will have to carry a bigger load because of the uncertainty at tailback.

Heisman Trophy winner Tim Tebow and receiver Percy Harvin will lead a talented offense, especially if USC transfer Emmanuel Moody emerges as a strong tailback. The Gators lacked a running game to complement Tebow last season. The defense continues to be a concern, however, especially after co-coordinator Greg Mattison left for the Baltimore Ravens. Coach Urban Meyer worked quickly and hired former Iowa State coach Dan McCarney to help on defense.

The defending national champion Tigers lose a boatload of talent, including quarterback Matt Flynn, tailback Jacob Hester and receiver Early Doucet on offense. The losses on defense are even bigger, with All-Americans Glenn Dorsey and Craig Steltz leaving. But coach Les Miles still has a full cupboard of talent. QB Ryan Perrilloux will have to come through if the Tigers are going to defend their SEC championship.

Tigers coach Tommy Bowden might be poised to win the ACC championship at last. After getting a contract extension, Bowden assembled one of the best recruiting classes in the country. He also persuaded junior tailback James Davis and receiver Aaron Kelly to stay in school. Underrated quarterback Cullen Harper comes back to lead what might be the ACC's best offense.

A 52-34 loss to Texas in the Holiday Bowl showed the Sun Devils still have plenty of work to do under coach Dennis Erickson. QB Rudy Carpenter returns, but the Sun Devils will have to rebuild an offensive line that couldn't protect the quarterback in 2007. Safety Josh Barrett and linebacker Robert James are big losses on defense. The recruiting class brings instant help, with five offensive linemen and five juco transfers coming in.

The Hokies will have to be better on offense than they were in 2007 because their defense will have to overcome heavy personnel losses. Linebackers Xavier Adibi and Vince Hall are both gone, along with end Chris Ellis and cornerback Brandon Flowers. Will coach Frank Beamer continue to rotate quarterbacks Sean Glennon and Tyrod Taylor, a mix that worked at the end of the 2007 season? Tailback Branden Ore needs to have a better offseason than he did a year ago.

QB Graham Harrell and receiver Michael Crabtree might have Texas Tech poised to become the biggest surprise of 2008. The Red Raiders should be able to score plenty of points again, and with eight starters coming back on defense, they might even be equipped to stop opponents this season. Road games at Texas A&M, Kansas and Oklahoma are big tests.

Kansas State transfer Allan Evridge is in line to replace quarterback Tyler Donovan, and his job will be easier after tight end Travis Beckum decided to return to school for one more season. Tailback P.J. Hill will have to stay healthy for the Badgers to reach their full potential, but Zach Brown and Lance Smith emerged as capable runners when Hill was hurt last season. A five-game stretch against Michigan, Ohio State, Penn State, Iowa and Illinois at midseason is more than daunting.

For all their warts last season, the Volunteers still finished 10-4 and beat Wisconsin 21-17 in the Outback Bowl. The offense will get a makeover in 2008 because QB Erik Ainge exhausted his eligibility and offensive coordinator David Cutcliffe was named Duke's head coach. Two other assistant coaches left, and Phillip Fulmer hired Richmond coach Dave Clawson as offensive coordinator, Richmond assistant Latrell Scott as wide receivers coach and Florida assistant Stan Drayton as running backs coach. Getting safety Demetrice Morley back, after he spent the 2007 season at a nearby technical college to improve his grades, should be a big boost to the secondary. The Vols play at UCLA in Week 2 and have SEC road games at Georgia, Auburn and South Carolina.

Can Jayhawks coach Mark Mangino find lightning in a bottle again in 2008? It won't be easy, especially after All-America cornerback Aqib Talib and offensive tackle Anthony Collins entered the NFL draft as juniors. Kansas also must replace tailback Brandon McAnderson, the team's leading rusher. QB Todd Reesing and nine returning starters on defense ensure the Jayhawks won't fall off the map.

The Tigers figure to fly under the radar again, which is when coach Tommy Tuberville's teams tend to play their best. The offense will have a new look after Tuberville hired Troy's Tony Franklin to replace offensive coordinator Al Borges. Defensive coordinator Will Muschamp left for Texas. QB Kodi Burns replaces much-maligned Brandon Cox, and the Tigers have to do a better job of running the football. Defensive end Quentin Groves and tackles Pat Sims and Josh Thompson are the biggest losses on defense.

With 17 starters coming back, coach Joe Paterno might be poised to make one last run at a Big Ten championship. Junior Daryll Clark is in line to replace QB Anthony Morelli, so the Nittany Lions might employ a spread offense in 2008. Top receivers Deon Butler, Jordan Norwood and Derrick Williams will all return. Replacing inside linebacker Dan Connor and junior cornerback Justin King, who left for the NFL draft, are priorities on defense.

The Ducks salvaged their season with a 56-21 rout of South Florida in the Sun Bowl, proving there was more to Oregon than QB Dennis Dixon. Coach Mike Bellotti will have to replace Dixon and star running back Jonathan Stewart, who left for the NFL draft as a junior. The Ducks also will have to replace two starters on the offensive line and the heart of their defense. Tailback Jeremiah Johnson is coming back from a torn ACL that shortened his 2007 season.

After winning 11 games each of the past two seasons, the Cougars might contend for a BCS at-large berth in 2008. QB Max Hall played very well in his first season as a starter after missing a couple of seasons while serving a Mormon mission. The defense will have to be rebuilt, with several key linebackers and defensive backs departing.

Did you hear that Mountaineers coach Rich Rodriguez left for Michigan? His messy divorce from West Virginia overshadowed the Mountaineers' convincing 48-28 rout of Oklahoma in the Fiesta Bowl. QB Pat White and speedy tailback Noel Devine are coming back, but tailback Steve Slaton, receiver Darius Reynaud and defensive end Johnny Dingle entered the NFL draft as juniors. New coach Bill Stewart expects the Mountaineers to win games and contend for the Big East championship in his first season.

The Cavaliers seemed capable of a big season in 2008, but a rough start to the offseason -- academic problems and a few defections -- will make it tougher for coach Al Groh. The Cavaliers salvaged a 9-4 season in 2007 by winning several close games. Virginia is capable of doing it again.

After beating West Virginia 13-9 in one of the biggest upsets of 2007, the Panthers finally seemed poised to turn the corner under coach Dave Wannstedt. QB Pat Bostick and tailback LeSean McCoy both played remarkably well as freshmen, and the defense showed some bite at season's end. If the Panthers can learn to win close games -- they lost four games by seven or fewer points last season -- they might be one of the country's biggest surprises.

Coach Ron Zook's rebuilding job might be more difficult this season now that star tailback Rashard Mendenhall left for the NFL draft after his junior season. QB Juice Williams will have to carry an even bigger load in the spread offense, and receiver Arrelious Benn will have to be more involved. Replacing star linebacker J Leman on defense is a top priority. The Illini will get help from another nationally ranked recruiting class.

The Gamecocks hoped to challenge for an SEC East title in 2007, but they finished the season with a five-game losing streak and a 6-6 record. South Carolina ultimately was undone by too many injuries and not enough depth. Coach Steve Spurrier has recruited well, so the Gamecocks should begin to reap the rewards of his efforts. Spurrier hired Ellis Johnson to replace defensive coordinator Tyrone Nix. Redshirt freshman Stephen Garcia might be Carolina's quarterback of the future.

The Bulldogs were very explosive at the end of the 2007 season, scoring 30 or more points in eight of their last nine games, including a 40-28 win over Georgia Tech in the Humanitarian Bowl. After an uncharacteristic 4-8 finish in 2006, coach Pat Hill redeemed himself with a 9-4 record. With QB Tom Brandstater and tailback Ryan Mathews returning, the Bulldogs again should be explosive on offense.

Mark Schlabach covers college football and men's college basketball for ESPN.com. You can contact him at schlabachma@yahoo.com.